The BBC committed a "major breach" of industry standards by omitting to mention that the presenter of a programme about Gaza was the offspring of a Hamas official, as ruled by regulatory body Ofcom.
An probe by the broadcasting watchdog into Gaza: How to Survive a Warzone has concluded that the film was "materially misleading".
The head of the BBC had earlier expressed regret, saying there had been "a serious error in relation to factual correctness".
Ofcom has instructed the corporation to air a peak-time statement about its decisions.
"As this represents a significant violation of our rules, we are directing the broadcaster to air a announcement of our conclusions against it on BBC2 at nine o'clock in the evening, with a timing to be determined," it said.
'Possibility to Erode Confidence'
The watchdog's statement said: "Our investigation concluded that the programme's omission to reveal that the narrator's parent occupied a post in the Hamas-run authority was substantially inaccurate.
"It meant that the audience did not have essential details which may have been extremely pertinent to their assessment of the voice and the content he shared.
"Credibility is at the core of the connection between a television network and its viewers, notably for a public service broadcaster such as the public broadcaster.
"This oversight had the potential to undermine the very considerable degrees of trust that audiences would have put in a factual film from the broadcaster about the conflict in Gaza."
The documentary was pulled from the online platform in the month of February after the narrator's personal associations were revealed, and in this past July an broadcaster's internal assessment concluded it breached the corporation's journalistic standards on accuracy.
A representative for the broadcaster stated: "The Ofcom ruling is in agreement with the results of Peter Johnston's review, that there was a serious error in the programme in relation to the broadcaster's journalistic policies on factual correctness, which reflects clause 2.2 of the regulator's media standards.
"We issued an apology for this and we comply with Ofcom's decision in full. We will follow the directive as soon as the date and wording are determined."
